The objective of this proposal is to find a means to enhance killing of a radioresistant cell population by moderate hyperthermia. Current findings have provided us with some interesting approaches. Because HeLa cells under a deprived state of oxygen and glucose become extremely heat sensitive, we plan to study in detail the interaction of glucose concentration, ambient oxygen concentration and the temperature of the cell survival. Studies will be directed to obtain maximum synergistic kill of cells in G1 and S phase for combination studies with radiation, using synchronized HeLa cell system. In addition, studies will be carried out to examine whether specific metabolic pathways of glucose metabolism are altered. The results of these studies may provide important clues for a better understanding of the mechanism of heat inactivation of cancer cells and may lead to better methods of controlling cancer.